1. Field of the Invention
The present disclosure relates to a cartridge removably mounted in a main assembly of an image forming apparatus, and a cover member mounted on the cartridge.
2. Description of the Related Art
In an image forming apparatus, such as a copying machine, printer, and facsimile machine, that uses electrophotographic image-forming process, an electrostatic latent image formed on an image bearing member, such as a photosensitive drum, is developed by a developing unit for visualization as a toner image. In conventionally known image forming apparatuses using such electrophotographic image-forming process, a developing unit formed as a cartridge (a developing cartridge), is removably mounted in a main assembly of the image forming apparatus. Since the developing unit is provided as the cartridge, a user can replace the developing unit.
In some developing cartridges, a developing roller, which carries a developer for developing an electrostatic latent image on an image bearing member, is partially exposed outside a frame of the developing cartridge. Such developing cartridges may be provided with a cover member that covers the exposed part of the developing roller to protect the developing roller during transportation (see Japanese Patent Application Laid-Open No. 2004-264757).
A cover member for covering a developing roller is discussed in Japanese Patent Application Laid-Open No. 2000-019839. In the configuration discussed in Japanese Patent Application Laid-Open No. 2000-019839, a cover has a sealing member made of urethane foam. When the cover member covers an exposed part of a developing roller, space formed between a peripheral portion of the exposed part and the cover member is filled with the sealing member, thereby preventing leaking of a developer from the exposed part into the surrounding area.
During transportation of a developing cartridge, a developer may leak from the inside of the developing cartridge due to physical shock applied to the developing cartridge. Also, at the time of start of using a developing cartridge, friction is generated between a developing roller and a developer supply roller which supplies a developer to the developing roller. To reduce such friction, the developer may be applied in advance to the developing roller and the developer supply roller. The developer may run off the developing roller at an exposed part during transportation of the developing cartridge, and may flow between the developing cartridge and a cover mounted on the developing cartridge, and then to a grip portion of the developing cartridge. The developer adhering to the grip portion can stain the user's hands.
If a sealing member is provided to the cover to surround the peripheral portion of the exposed part of the developing roller as discussed in Japanese Patent Application Laid-Open No. 2000-019839, the number of components is increased.